Heat transfer fluid additive composition

ABSTRACT

Disclosed herein is a heat transfer fluid additive composition comprising: greater than or equal to 10 weight percent (wt %) of a carboxylic acid, based on the total weight of the composition; an azole compound; and a base, wherein the base is present in an amount sufficient to obtain a pH 8-10.5 when diluted by 50 volume % with water. The heat transfer fluid additive composition can be combined with other components to form a heat transfer fluid. The heat transfer fluid can be used in a heat transfer system.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.13/606,527, filed Sep. 7, 2012, the contents of which are incorporatedherein by reference.

BACKGROUND

Modern vehicle engines generally require a heat transfer fluid (liquidcoolant) to provide long-lasting, year-round protection of their coolingsystems. The primary requirements of heat transfer fluids are that theyprovide efficient heat transfer to control and maintain enginetemperature for efficient fuel economy and lubrication, and preventengine failures due to freeze-up, boiling-over, or over-heating. Thereare a variety of types of heat transfer fluids which comprise asignificant quantity of solvent or solvents. As the cost oftransportation and packaging rises, the advantages of creating a heattransfer fluid closer to the point of use become clear. Difficultiesarise however in the wide range of formulations for heat transfer fluidsand the stability issues associated with additive composition solutions.

There is an ongoing need for a heat transfer fluid additive compositionhaving good storage stability and wide ranging utility.

BRIEF DESCRIPTION

This need is met, at least in part, by a heat transfer fluid additivecomposition comprising greater than or equal to 10 weight percent (wt %)of a carboxylate, based on the total weight of the composition; an azolecompound; a base; and water, wherein the base is present in an amountsufficient to obtain a pH of 7 to 10.5 when the heat transfer additivecomposition is diluted by 50 volume % with water. The heat transferfluid additive composition can be combined with other components to forma heat transfer fluid. The heat transfer fluid additive composition canbe combined with an existing heat transfer fluid to modify the heattransfer fluid. The heat transfer fluid can be used in a heat transfersystem with or without other components or existing heat transfer fluid.

DETAILED DESCRIPTION

Disclosed herein are heat transfer fluid additive compositions thatfacilitate the preparation of heat transfer fluids having a wide rangeof formulations. The additive composition can also be employed to modifythe composition of an existing heat transfer fluid to provide improvedperformance.

The heat transfer fluid additive composition can be free of silicate,borate and amines. The nitrate content can be less than 100 parts permillion by weight (ppm), or, more specifically, less than 50 ppm byweight based on the total weight of the heat transfer fluid. Theadditive composition can also be free of glycols, glycerols, glycerin,and/or other solvents/freeze point depressants, or a combinationthereof.

The carboxylate has 6 to 20 carbon atoms. The term “carboxylate” isinclusive of carboxylic acid, salt thereof, and combinations of acarboxylic acid and carboxylic acid salt. The carboxylate may comprise asingle or multiple carboxyl groups and may be linear or branched. It isexpressly contemplated that combinations of carboxylates may be used andare encompassed by the term “carboxylate” or “carboxylic acid”.Exemplary aliphatic carboxylates include 2-ethyl hexanoic acid, hexanoicacid, heptanoic acid, octanoic acid, neodecanoic acid, decanoic acid,nonanoic acid, isoheptanoic acid, dodecanoic acid, sebacic acid, adipicacid, pimelic acid, suberic acid, azelaic acid, dodecanedioic acid, andcombinations of two or more of the foregoing. Exemplary aromaticcarboxylates include benzoic acid, toluic acid or methylbenzoic acid,tert-butyl benzoic acid, alkoxy benzoic acid, e.g., methoxybenzoic acid(or o, p, m-anisic acid), salicylic acid, phthalic acid, isophthalicacid, terephthalic acid, phenylacetic acid, mandelic acid,1,2,4-benzenetricarboxylic acid, and combinations of two or more of theforegoing.

In the heat transfer fluid, additive composition the carboxylate ispresent in an amount greater than or equal to 10 wt %, based on thetotal weight of the heat transfer fluid additive composition. Withinthis range, the amount can be greater than or equal to about 15 wt %,or, more specifically, greater than or equal to about 20 wt %. Theamount can be less than or equal to about 90 wt %, or, morespecifically, less than or equal to about 80 wt %.

The heat transfer fluid additive composition comprises an azole.Exemplary azoles include benzotriazole, tolyltriazole, methylbenzotriazole (e.g., 4-methyl benzotriazole and 5-methyl benzotriazole),butyl benzotriazole, and other alkyl benzotriazoles (e.g., the alkylgroup contains from 2 to 20 carbon atoms), mercaptobenzothiazole,thiazole and other substituted thiazoles, imidazole, benzimidazole, andother substituted imidazoles, indazole and substituted indazoles,tetrazole, tetrahydrotolyltriazole, and substituted tetrazoles.Combinations of two or more of the foregoing azoles may also be used andcombinations of azoles are included in the term “azole”.

In the heat transfer fluid additive composition, the azole compound canbe present in an amount of about 0.01 wt % to about 10 wt %, based onthe total weight of the heat transfer fluid additive composition. Withinthis range, the azole compound can be present in an amount greater thanor equal to about 0.3 wt %, or, more specifically, greater than or equalto about 0.5 wt %. Also within this range, the azole compound can bepresent in an amount less than or equal to about 9 wt %, or, morespecifically, less than or equal to about 8 wt %.

Exemplary bases include sodium hydroxide, potassium hydroxide, and thelike. The base is present in an amount sufficient to obtain a pH ofabout 7 to about 10.5 when the heat transfer fluid additive compositionis diluted by 50 volume % with water. Within this pH range, the pH canbe greater than or equal to about 7.5, or, more specifically, greaterthan or equal to about 8.

In the heat transfer fluid additive composition, water can be present inan amount of about 10 wt % to 90wt %, based on the total weight of theheat transfer fluid additive composition. Within this range, water canbe present in an amount less than or equal to 50 wt %, or, morespecifically, less than or equal to 40 wt %, or, more specifically, lessthan or equal to 25 wt %.

The heat transfer fluid additive composition may further comprise one ormore optional components such as a non-aqueous solvent, an inorganicphosphate, lithium ions, magnesium ions, calcium ions, an acrylate basedpolymer, a phosphonocarboxylate, a phosphinocarboxylate, antifoamingagent or defoamer, dispersant, scale inhibitor, surfactant, colorant andcombinations of two or more of the foregoing optional components.

Exemplary non-aqueous solvents include glycols, glycerin, or acombination thereof. Exemplary glycols include ethylene glycol,propylene glycol (including 1,2-propylene glycol and 1,3-propyleneglycol), diethylene glycol, triethylene glycol, dipropylene glycol,butylene glycol, and combinations of two or more of the foregoingnon-aqueous solvents.

The non-aqueous solvent can be present in an amount of about 10 wt % toabout 85 wt %, based on the total weight of the heat transfer fluidadditive composition. Within this range, the non-aqueous solvent can bepresent in an amount less than or equal to about 40 wt %, or, morespecifically, less than or equal to about 20 wt %.

Exemplary inorganic phosphates include phosphoric acid, sodiumorthophosphate, potassium orthophosphate, sodium pyrophosphate,potassium pyrophosphate, sodium polyphosphate, potassium polyphosphate,sodium hexametaphosphate, potassium hexametaphosphate, and combinationsof two or more of the foregoing inorganic phosphates.

The inorganic phosphate can be present in an amount of about 1 wt % toabout 10 wt %, based on the total weight of the heat transfer fluidadditive composition. Within this range, the amount can be greater thanor equal to about 1.5 wt %, or, more specifically, greater than or equalto about 2 wt %. Also within this range, the amount can be less than orequal to about 6 wt %, or, more specifically, less than or equal toabout 4 wt %.

The lithium ions are derived from a lithium compound or compounds thatcan produce lithium ions upon dissolving in a water containing solutionat room temperature. The lithium compound can be an inorganic lithiumcompound such as lithium hydroxide, lithium phosphate, lithium borate,lithium nitrate, lithium perchlorate, lithium sulfate, lithiummolybdate, lithium vanadate, lithium tungstate, lithium carbonate, or acombination thereof. The lithium compound is soluble in the heattransfer fluid. Soluble, as used herein, is defined as dissolving suchthat no particulate matter is visible to the naked eye. The lithiumcompound can also be lithium salt formed between lithium ions and anorganic acid containing one or more carboxylic acid groups, such aslithium acetate, lithium benzoate, lithium polyacrylate, lithiumpolymaleate, lithium lactate, lithium citrate, lithium tartrate, lithiumgluconate, lithium glucoheptonate, lithium glycolate, lithium glucarate,lithium succinate, lithium hydroxyl succinate, lithium adipate, lithiumoxalate, lithium malonate, lithium sulfamate, lithium formate, lithiumpropionate, lithium salt of aliphatic mono-, di- or tri-carboxylic acidor aromatic mono-, di- or tri-carboxylic acid, and combinations of theforegoing lithium compounds.

The magnesium ions are derived from a magnesium compound that canproduce magnesium ions upon dissolving in a water containing solution atroom temperature. The magnesium compound can be an inorganic magnesiumcompound such as magnesium nitrate, magnesium sulfate, magnesiummolybdate, magnesium tungstate, magnesium vanadate, magnesiumperchlorate, magnesium hydroxide or a combination thereof. The magnesiumcompound is soluble in the heat transfer fluid. Soluble, as used herein,is defined as dissolving such that no particulate matter is visible tothe naked eye. The magnesium compound can also be magnesium salt formedbetween magnesium ions and an organic acid containing one or morecarboxylic acid groups, such as magnesium polyacrylate, magnesiumpolymaleate, magnesium lactate, magnesium citrate, magnesium tartrate,magnesium gluconate, magnesium glucoheptonate, magnesium glycolate,magnesium glucarate, magnesium succinate, magnesium hydroxysuccinate,magnesium adipate, magnesium oxalate, magnesium malonate, magnesiumsulfamate, magnesium formate, magnesium acetate, magnesium propionate,magnesium salt of aliphatic tri-carboxylic acid or aliphatictetra-carboxylic acid, and combinations of the foregoing magnesiumcompounds.

The calcium ions are derived from a calcium compound that can producecalcium ions upon dissolving in a water containing solution at roomtemperature. The calcium compound can be an inorganic calcium compoundsuch as calcium nitrate, calcium chloride, calcium perchlorate, calciummolybdate, calcium tungstate, calcium vanadate, calcium hydroxide, or acombination thereof. The calcium compound is soluble in the heattransfer fluid. Soluble, as used herein, is defined as dissolving suchthat no particulate matter is visible to the naked eye. The calciumcompound can also be calcium salt formed between calcium ions and anorganic acid containing one or more carboxylic acid groups, such ascalcium polyacrylate, calcium polymaleate, calcium lactate, calciumcitrate, calcium tartrate, calcium gluconate, calcium glucoheptonate,calcium glycolate, calcium glucarate, calcium succinate, calciumhydroxysuccinate, calcium adipate, calcium oxalate, calcium malonate,calcium sulfamate, calcium formate, calcium acetate, calcium propionate,calcium salts of aliphatic tri-carboxylic acid or aliphatictetra-carboxylic acid, and combinations of the foregoing calciumcompounds.

The acrylate based polymer is a water soluble polymer (average molecularweight of 200 to 200,000 Daltons). Exemplary acrylate polymers includepolyacrylates, acrylate based polymers, copolymers, terpolymers, andquadpolymers, such as acrylate/acrylamide copolymers, polymethacrylates,polymaleic acids or maleic anhydride polymers, maleic acid basedpolymers, their copolymers and terpolymers, modified acrylamide basedpolymers, including polyacrylamides, acrylamide based copolymers andterpolymers. In general, water soluble polymers suitable for use includehomo-polymers, copolymers, terpolymer and inter-polymers having (1) atleast one monomeric unit containing C₃ to C₁₆ monoethylenicallyunsaturated mono- or dicarboxylic acids or their salts; or (2) at leastone monomeric unit containing C₃ to C₁₆ monoethylenically unsaturatedmono- or dicarboxylic acid derivatives such as amides, nitriles,carboxylate esters, acid halides (e.g., chloride), and acid anhydrides,and combination thereof. In some embodiments, the acrylate based polymercomprises a phosphinopolyacrylate.

Phosphonocarboxylates are phosphonated compounds having the generalformula

H[CHRCHR]_(n)—PO₃M₂

wherein at least one R group in each unit is a COOM, CH₂OH, sulphono orphosphono group and the other R group which may be the same as, ordifferent from, the first R group, is a hydrogen or a COOM, hydroxyl,phosphono, sulphono, sulphato, C₁₋₇ alkyl, C₁₋₇ alkenyl group or acarboxylate, phosphono, sulphono, sulphato and/or hydroxyl substitutedC₁₋₇ alkyl or C₁₋₇ alkenyl group, n is 1 or an integer greater than 1,and each M is hydrogen or an alkali metal ion such as a sodium ion,potassium ion and the like. Furthermore, at least one COOM group will bepresent in one of the R groups. Preferably, the phosphonocarboxylatesare phosphonated oligomers or mixture of phosphonated oligomers ofmaleic acid, of the formula H[CH(COOM)CH(COOM)]_(n)—PO₃M₂, where n is 1or an integer greater than 1, and M is a cationic species (e.g., alkalimetal cations) such that the compound is water soluble. Exemplaryphosphonocarboxylates include phosphonosuccinic acid,1-phosphono-1,2,3,4-tetracarboxybutane, and1-phosphono-1,2,3,4,5,6-hexacarboxyhexane. The phosphonocarboxylates canbe a mixture of compounds having the preceding formula with differingvalues for “n”. The mean value of “n” can be 1 to 2, or, morespecifically, 1.3 to 1.5. The synthesis of the phosphonocarboxylates isknown and described in U.S. Pat. No. 5,606,105. Thephosphonocarboxylates are separate and different from the carboxylicacids described above. The carboxylic acid described above consists ofcarbon, hydrogen and oxygen and are free of non-oxygen heteroatoms.

Phosphinocarboxylates are compounds having the general formula

H[CHR¹CHR¹]_(n)—P(O₂M)—[CHR²CHR²]_(m)H

wherein at least one R¹ group in each unit is a COOM, CH₂OH, sulphono orphosphono group and the other R¹ group which may be the same as, ordifferent from, the first R¹ group, is a hydrogen or a COOM, hydroxyl,phosphono, sulphono, sulphato, C₁₋₇ alkyl, C₁₋₇ alkenyl group or acarboxylate, phosphono, sulphono, sulphato and/or hydroxyl substitutedC₁₋₇ alkyl or C₁₋₇ alkenyl group, n is an integer equal to or greaterthan 1, and each M is hydrogen or an alkali metal ion such as a sodiumion, potassium ion and the like. Similarly, at least one R² group ineach unit is a COOM, CH₂OH, sulphono or phosphono group and the other R²group which may be the same as, or different from, the first R² group,is a hydrogen or a COOM, hydroxyl, phosphono, sulphono, sulphato, C₂₋₇alkyl, C₂₋₇ alkenyl group or a carboxylate, phosphono, sulphono,sulphato and/or hydroxyl substituted C₁₋₇ alkyl or C₁₋₇ alkenyl group, mis an integer equal to or greater than 0. Furthermore, at least one COOMgroup will be present in one of the R¹ and R² groups. Exemplaryphosphinocarboxylates include phosphinicosuccinic acid and water solublesalts, phosphinicobis (succinic acid) and water soluble salts andphosphinicosuccinic acid oligomer and salts as described in U.S. Pat.Nos. 6,572,789 and 5,018,577. The phosphonocarboxylates can be a mixtureof compounds having the preceding formula with differing values for “n”and “m”. The phosphinocarboxylates are separate and different from thecarboxylic acids described above.

Exemplary surfactants include fatty acid esters, such as sorbitan fattyacid esters, polyalkylene glycols, polyalkylene glycol esters,copolymers of ethylene oxide (EO) and propylene oxide (PO),polyoxyalkylene derivatives of a sorbitan fatty acid ester, and mixturesthereof. The average molecular weight of the non-ionic surfactants canbe about 55 to about 300,000, or, more specifically about 110 to about10,000. Suitable sorbitan fatty acid esters include sorbitan monolaurate(e.g., sold under trade name Span® 20, Arlacel® 20, S-MAZ® 20M1),sorbitan monopalmitate (e.g., Span® 40 or Arlacel® 40), sorbitanmonostearate (e.g., Span® 60, Arlacel® 60, or S-MAZ® 60K), sorbitanmonooleate (e.g., Span® 80 or Arlacel® 80), sorbitan monosesquioleate(e.g., Span® 83 or Arlacel® 83), sorbitan trioleate (e.g., Span® 85 orArlacel® 85), sorbitan tridtearate (e.g., S-MAZ® 65K), sorbitanmonotallate (e.g., S-MAZ® 90). Suitable polyalkylene glycols includepolyethylene glycols, polypropylene glycols, and mixtures thereof.Examples of polyethylene glycols suitable for use include CARBOWAX™polyethylene glycols and methoxypolyethylene glycols from Dow ChemicalCompany, (e.g., CARBOWAX PEG 200, 300, 400, 600, 900, 1000, 1450, 3350,4000 & 8000, etc.) or PLURACOL® polyethylene glycols from BASF Corp.(e.g., Pluracol® E 200, 300, 400, 600, 1000, 2000, 3350, 4000, 6000 and8000, etc.). Suitable polyalkylene glycol esters include mono- anddi-esters of various fatty acids, such as MAPEG® polyethylene glycolesters from BASF (e.g., MAPEG® 200ML or PEG 200 Monolaurate, MAPEG® 400DO or PEG 400 Dioleate, MAPEG® 400 MO or PEG 400 Monooleate, and MAPEG®600 DO or PEG 600 Dioleate, etc.). Suitable copolymers of ethylene oxide(EO) and propylene oxide (PO) include various Pluronic and Pluronic Rblock copolymer surfactants from BASF, DOWFAX non-ionic surfactants,UCON™ fluids and SYNALOX lubricants from DOW Chemical. Suitablepolyoxyalkylene derivatives of a sorbitan fatty acid ester includepolyoxyethylene 20 sorbitan monolaurate (e.g., products sold undertrademarks TWEEN 20 or T-MAZ 20), polyoxyethylene 4 sorbitan monolaurate(e.g., TWEEN 21), polyoxyethylene 20 sorbitan monopalmitate (e.g., TWEEN40), polyoxyethylene 20 sorbitant monostearate (e.g., TWEEN 60 or T-MAZ60K), polyoxyethylene 20 sorbitan monooleate (e.g., TWEEN 80 or T-MAZ80), polyoxyethylene 20 tristearate (e.g., TWEEN 65 or T-MAZ 65K),polyoxyethylene 5 sorbitan monooleate (e.g., TWEEN 81 or T-MAZ 81),polyoxyethylene 20 sorbitan trioleate (e.g., TWEEN 85 or T-MAZ 85K) andthe like.

Exemplary antifoam agents include polydimethylsiloxane emulsion basedantifoams. They include PC-5450NF from Performance Chemicals, LLC inBoscawen, N.H.; CNC antifoam XD-55 NF and XD-56 from CNC Internationalin Woonsocket in R.I. Other antifoams suitable for use in the instantinvention include copolymers of ethylene oxide (EO) and propylene oxide(PO), such as Pluronic L-61 from BASF.

Generally, the optional antifoam agents may comprise a silicone, forexample, SAG 10 or similar products available from OSI Specialties, DowComing or other suppliers; an ethylene oxide-propylene oxide (EO-PO)block copolymer and a propylene oxide-ethylene oxide-propylene oxide(PO-EP-PO) block copolymer (e.g., Pluronic L61, Pluronic L81, or otherPluronic and Pluronic C products); poly(ethylene oxide) orpoly(propylene oxide), e.g., PPG 2000 (i.e., polypropylene oxide with anaverage molecular weight of 2000); a hydrophobic amorphous silica; apolydiorganosiloxane based product (e.g., products containingpolydimethylsiloxane (PDMS), and the like); a fatty acid or fatty acidester (e.g., stearic acid, and the like); a fatty alcohol, analkoxylated alcohol and a polyglycol; a polyether polylol acetate, apolyether ethoxylated sorbital hexaoleate, and a poly(ethyleneoxide-propylene oxide) monoallyl ether acetate; a wax, a naphtha,kerosene and an aromatic oil; and combinations comprising one or more ofthe foregoing antifoam agents.

The heat transfer fluid additive composition can be used in severalways. It may be combined with water, a non-aqueous solvent, orcombination of water and a non-aqueous solvent to form a heat transferfluid. It may be added to an existing heat transfer fluid to modify thecomposition of the heat transfer fluid. It may be added to a heattransfer system comprising a heat transfer fluid to modify the heattransfer fluid.

A method of making a heat transfer fluid comprises combining a heattransfer additive composition with water, a non-aqueous solvent, or acombination of water and a non-aqueous solvent wherein the heat transferadditive composition comprises greater than or equal to 10 weightpercent (wt %) of a carboxylate, based on the total weight of thecomposition; an azole compound; a base; and water, wherein the base ispresent in an amount sufficient to obtain a pH of 7 to 10.5 when theheat transfer additive composition is diluted by 50 volume % with water.Non-aqueous solvents useful in making the heat transfer fluid includethose described above in relation to the heat transfer fluid additivecomposition as well as in alcohol having one to 4 carbon atoms (e.g.,methanol, ethanol, propanol, butanol) and combinations comprising two ormore of the non-aqueous solvents described herein.

The heat transfer additive composition can be combined with water and/ornon-aqueous solvent in a volume ratio in the range of 1 to 5 to 1 to 40.Within this range, the volume ratio can be less than or equal to 1 to 9,or, less than or equal to 1 to 5. Also within this range, the volumeratio can be greater than or equal to 1 to 18, or, greater than or equalto 1 to 36.

A method of making a modified heat transfer fluid comprises combining aheat transfer additive composition with an existing heat transfer fluidto form a modified heat transfer fluid wherein heat transfer fluidadditive comprises greater than or equal to 10 weight percent (wt %) ofa carboxylate, based on the total weight of the composition; an azolecompound; a base; and water, wherein the base is present in an amountsufficient to obtain a pH of 7 to 10.5 when the heat transfer additivecomposition is diluted by 50 volume % with water. The existing heattransfer fluid may be new (used outside a heat transfer system) or theexisting heat transfer fluid may be used (already in contact with a heattransfer system).

The heat transfer additive composition can be combined with the existingheat transfer fluid in a volume ratio in the range of 1 to 10 to 1 to50. Within this range, the volume ratio can be greater than or equal to1 to 35, or, greater than or equal to 1 to 25. Also within this range,the volume ratio can be less than or equal to 1 to 10, or, less than orequal to 1 to 20.

It is also contemplated that in some applications, such as heavy dutyengines, it may be desirable to incorporate one or more additionalcorrosion inhibitors such as nitrites, molybdates, and salts thereof.

The heat transfer additive composition is further demonstrated by thefollowing non-limiting examples.

EXAMPLES

The heat transfer additive compositions shown in Table 1 were made bycombining the listed ingredients. The amounts shown in the table are inweight percent based on the total weight of the additive composition.PM-5150 is an antifoam commercially available from Prestone ProductsCorporation. Chromatint Orange 1735 is a colorant commercially availablefrom Chromatech Incorporated. Dye X-0714 is a colorant commerciallyavailable from Chromatech Incorporated. Uranine dye is commerciallyavailable from Chromatech Incorporated.

TABLE 1 Concentrate A Concentrate B Concentrate C Concentrate DConcentrate E Ethylene Glycol 37.1720 36.9670 34.9983 30.5685 26.5582Sodium Tolyltriazole 2.3600 2.3600 2.3599 2.6067 2.7654 Sodium Hydroxide9.8690 9.8690 9.8695 10.9830 11.6631 Neo Decanoic Acid 9.5900 9.59009.5895 10.5704 11.1373 2-Ethyl Hexanoic 28.7700 28.7700 28.7786 31.673733.4404 acid Deionized water 12.2290 12.2290 12.2294 13.5896 14.4285PM-5150 antifoam 1.9999 Chromatint Orange 0.2150 1735 Dye X-0714 0.1750Uranine Dye, 40% 0.0100 0.0082 0.0071 Total, % 100.0000 100.0000100.0000 100.0000 100.0000 pH @ 50% dilution 9.5 9.5 — 10.01 10.34 withwater

Concentrate B was diluted with differing types of diluents and indiffering amounts to form Test Solutions as shown in Table 2. Thecomposition of the test water referred to in Table 2 is shown in Table3. The Test Solutions were tested according to ASTM D4340 and D1384.Amounts in Table 2 are in parts by weight. The amounts in Table 3 are inweight percent.

TABLE 2 Test Test Test Test Solution Solution Solution Solution A B C EConcentrate B 175 175 175 175 Ethylene glycol 1370 685 Test Water 20552055 1713 1370 Commercial Coolant Concentrate 1370 1027 2055 TestResults from ASTM D4340 mg/cm²/wk, water cleaned, 25 v % −0.05 −0.050.01 0.03 coolant mg/cm²/wk, acid cleaned, 25 v % −0.04 −0.01 0.06 0.10coolant Test Results from ASTM D1384 coupon weight loss in milligrams,average of triplicate tests Copper, UNS C11000 1.2 1.4 1.0 2.3 ASTMSolder, SAE 3A 0.0 −0.3 −0.4 0.6 Brass, UNS C26000 −1.5 0.0 −0.2 0.6Carbon Steel, UNS G10200 −0.7 −0.7 −0.3 −0.2 Cast Iron, UNS F10007 −2.3−1.4 −1.0 −1.0 Cast Aluminum, UNS A23190 4.0 3.1 1.1 −1.1

The commercial coolant concentrate was an Extended Life OAT type coolantconcentrate. “Water cleaned” refers to taking the test sample at the endof test and first water cleaning it and determining the corrosion rate.“Acid cleaned” refers to taking the same test sample and doing an acidcleaning per ASTM D4340. These two set of numbers then can be comparedto provide additional information. A comparison of these numbers showsif there is a deposit on the sample surface (water cleaning will notremove it but acid cleaning will).

TABLE 3 wt % Deionized water 99.8909 Sodium Sulfate, Na₂SO₄ 0.0148Sodium Chloride, NaCl 0.0165 Sodium Formate, HCOONa 0.0138 FerricNitrate, Fe(NO₃)₃ 0.0217 Aluminum Nitrate, 0.0224 Al(NO₃)₃ CalciumCarbonate, CaCO₃ 0.0200

Concentrate B was also diluted with varying amounts of water and testedaccording to ASTM D4340 for the corrosion rate. Each solution alsocomprises 100 ppm of NaCl. These dilutions were tested according to ASTMD4340.

TABLE 4 Corrosion Rate wt % Concentrate B in DI water Water Washed, AcidWashed, and 100 ppm NaCl mg/cm²/wk mg/cm²/wk 2.5 0.05 0.22 10.0 −0.11−0.16 20.0 −0.12 −0.14 50.0 0.12 0.16 60.0 −0.02 0.03

Finally, varying concentrations of Concentrate B in deionized water weretested for the freezing point. This data is represented both inFahrenheit and Centigrade. Results are shown in Table 5. The pH of thesolutions was also tested.

TABLE 5 wt % wt % Freeze Freeze Concentrate B DI Water Point, ° F.Point, ° C. pH 70 30 −22.9 −30.5 — 60 40 −8.1 −22.3 — 50 50 2.3 −16.59.6 25 75 18.6 −7.4 9.2 10 90 27.9 −2.3 8.7 5 95 30.2 −1 8.6

The singular forms “a,” “an,” and “the” include plural referents unlessthe context clearly dictates otherwise. The endpoints of all rangesreciting the same characteristic or component are independentlycombinable and inclusive of the recited endpoint. All references areincorporated herein by reference. The terms “first,” “second,” and thelike herein do not denote any order, quantity, or importance, but ratherare used to distinguish one element from another. The variousembodiments and ranges described herein are combinable to the extentthat the description is not contradictory.

While typical embodiments have been set forth for the purpose ofillustration, the foregoing descriptions should not be deemed to be alimitation on the scope herein. Accordingly, various modifications,adaptations, and alternatives may occur to one skilled in the artwithout departing from the spirit and scope herein.

1. A heat transfer fluid additive composition consisting of: greaterthan or equal to about 10 wt % of a carboxylate; an azole compound; abase; a molybdate or nitrite, or salts thereof; water; and optionally,an antifoam agent, a colorant, a scale inhibitor, a surfactant, orcombinations thereof, wherein the composition is free of silicate. 2.The heat transfer fluid additive composition of claim 1 furthercomprising a non-aqueous solvent.
 3. The heat transfer fluid additivecomposition of claim 1, wherein the carboxylate is an aromaticcarboxylate.
 4. The heat transfer fluid additive composition of claim 1,wherein the carboxylate is an aliphatic carboxylate.
 5. The heattransfer fluid additive composition of claim 1, wherein the molybdate ornitrite is molybdate.
 6. The heat transfer fluid additive composition ofclaim 1, wherein the molybdate is calcium molybdate, lithium molybdate,magnesium molybdate, or combinations thereof.
 7. The additivecomposition of claim 1, wherein the carboxylate is greater than or equalto about 15 wt % of the composition.
 8. The additive composition ofclaim 1, wherein the carboxylate is greater than or equal to about 20 wt% of the composition.
 9. The additive composition of claim 1, whereinthe azole is about 0.01 to about 10 wt % of the composition.
 10. Theadditive composition of claim 1, wherein the azole is about 0.3 to about9 wt % of the composition.
 11. The additive composition of claim 1,wherein the azole is about 0.5 to about 8 wt % of the composition. 12.The additive composition of claim 1, wherein the base is sufficient toobtain a pH of about 7.5 to about 10.5 when the heat transfer additivecomposition is diluted by 50 volume % with water.
 13. The additivecomposition of claim 1, wherein the base is sufficient to obtain a pH ofabout 8 to 10.5 when the heat transfer additive composition is dilutedby 50 vol % with water.
 14. The additive composition of claim 1, whereinwater is about 10 wt % to about 70 wt % of the composition.
 15. Theadditive composition of claim 1, wherein water is about 10 wt % to about50 wt %.
 16. The additive composition of claim 1, wherein water ispresent in an amount of about 10 wt % to about 40 wt % of thecomposition.
 17. The additive composition of claim 1, wherein water isabout 10 wt % to about 25 wt % of the composition.
 18. The additivecomposition of claim 2, wherein the non-aqueous solvent comprisesglycol, glycerin, or a combination thereof.
 19. The additive compositionof claim 2, wherein the non-aqueous solvent is about 10 to about 85 wt %of the composition.
 20. The additive composition of claim 2, wherein thenon-aqueous solvent is about 10 to about 40 wt % of the composition. 21.The additive composition of claim 2, wherein the non-aqueous solvent isabout 10 to about 20 wt % of the composition.
 22. The heat transferfluid additive composition of claim 1, wherein the base is sodiumhydroxide.
 23. The heat transfer fluid additive composition of claim 18,wherein the glycol is ethylene glycol, propylene glycol, or mixturesthereof.
 24. The heat transfer fluid additive composition of claim 18,wherein the glycol is selected from the group consisting of ethyleneglycol; 1,2-propylene glycol; 1,3-propylene glycol; diethylene glycol;triethylene glycol; dipropylene glycol; butylene glycol; andcombinations thereof.
 25. The heat transfer fluid additive compositionof claim 1, wherein the azole is sodium tolyltriazole, benzotriazole, ora mixture of sodium tolyltriazole and benzotriazole.
 26. The heattransfer fluid additive composition of claim 1, wherein the azole isselected from the group consisting of benzotriazole; tolyltriazole;methyl benzotriazole; butyl benzotriazole; mercaptobenzothiazole;thiazole; ; substituted thiazoles; imidazole; benzimidazole; substitutedimidazoles; indazole; substituted indazoles; tetrazole;tetrahydrotolyltriazole; substituted tetrazoles; and combinationsthereof.
 27. The heat transfer fluid additive composition of claim 1,wherein the azole comprises a benzotriazole, wherein the benzotriazole'salkyl group contains 2 to 20 carbon atoms.
 28. The heat transfer fluidadditive composition of claim 1, wherein the carboxylate is neodecanoicacid and 2-ethyl hexanoic acid.
 29. The heat transfer fluid additivecomposition of claim 1, wherein the base is about 9 to about 12 weightpercent.
 30. A method of making a heat transfer fluid comprisingcombining the heat transfer fluid additive composition of claim 1 withwater, a non-aqueous solvent, or a combination of water and anon-aqueous solvent.
 31. The method of claim 30, wherein the additivecomposition is free of silicate, borate, and amines and has a nitratecontent less than 100 ppm.
 32. The method of claim 30, wherein thecarboxylate is greater than or equal to about 15 wt % of the additivecomposition.
 33. The method of claim 30, wherein the carboxylate isgreater than or equal to about 20 wt % of the additive composition. 34.The method of claim 30, wherein the azole is about 0.01 to about 10 wt %of the additive composition.
 35. The method of claim 30, wherein theazole is 2 about 0.5 to about 8 wt % of the additive composition. 36.The method of claim 30, wherein the base sufficient to obtain a pH ofabout 7.5 to about 10.5 when the heat transfer additive composition isdiluted by 50 vol % with water.
 37. The method of claim 30, wherein thebase is sufficient to obtain a pH of about 8 to 10.5 when the heattransfer additive composition is diluted by 50 vol % with water.
 38. Themethod of claim 30, wherein the water is about 10 wt % to about 70 wt %of the composition.
 39. The method of claim 30, wherein the water isabout 10 wt % to about 50 wt % of the additive composition.
 40. Themethod of claim 30, wherein the water is about 10 wt % to about 40 wt %of the additive composition.
 41. The method of claim 30, wherein thewater is about 10 wt % to about 25 wt % of the additive composition. 42.The method of claim 30, wherein the carboxylate is an aromaticcarboxylate.
 43. The method of claim 30, wherein the carboxylate is analiphatic carboxylate.
 44. The method of claim 30, wherein the molybdateor nitrite is molybdate.
 45. The method of claim 30, wherein themolybdate is calcium molybdate, lithium molybdate, magnesium molybdate,or combinations thereof.
 46. The method of claim 30, wherein the base issodium hydroxide.
 47. The method of claim 30, wherein the non-aqueoussolvent is a glycol.
 48. The method of claim 47, wherein the glycol isethylene glycol, propylene glycol, or a mixture of ethylene glycol andpropylene glycol.
 48. The method of claim 30, wherein the azole issodium tolyltriazole, benzotriazole, or a mixture of sodiumtolyltriazole and benzotriazole.
 49. The method of claim 30, wherein thecarboxylate is neodecanoic acid and 2-ethyl hexanoic acid.
 50. A methodof making a modified heat transfer fluid comprising combining the heattransfer fluid additive composition of claim 1 with an existing heattransfer fluid to form a modified heat transfer fluid.
 51. The method ofclaim 50, wherein the existing heat transfer fluid is not in contactwith a heat transfer system.
 52. The method of claim 52, wherein theexisting heat transfer fluid is in contact with a heat transfer system.